School me on TB sizing ...
Racer
Joined: Dec 2017
Posts: 485
Likes: 71
From: Massachusetts
No argument there, LT5 TB designed for LT5 engine and everything else. That's how you do it.Shaving and shaping are trying to squeeze the last drop of the LT1/LT4 TB for LT1/LT4 cars, not for the ZR1. The TB is king at part throttle (meaning influential), it is a Mr. nobody at WOT. At WOT it is just a 4-inch long duct extension, there isn't much more to it. You can increase that little length of duct to have a 1-mile diameter and, yes, it will flow very slow, very little pressure drop in it, yet the influence is nearly null in the system.
Last edited by Silvah Goat; Jun 21, 2019 at 08:12 AM.
Pro
Joined: Feb 2003
Posts: 745
Likes: 136
From: Detroit MI
100% of the part throttle "benefits" or "changes" can be realized through calibration of the driver request surface and ZERO hardware changes on a GENV engine. Current surprise level zero with regard to seeing similar WOT performance when the combination was not restricted by the throttle at full opening.
For me, it took a 7+L stroker with a 2.9L Whipple to see an engineering need for a change from the LT1 to Katech103 (only part on hand at the client) at full load. We were able to see a useful change in SCIP, MAP, and MAF after changing throttles on that combo, but we're talking four-digit power levels on a big PD combo there.
If one is talking about a stock-ish engine with a PD supercharger, the stock throttle may not be a restiction and you can get whatever part throttle response you want by asking for it correctly in the calibration tables. If you are blowing through the throttle (centrifugal or turbo), the bar moves even higher with regard to how much a stock TB is good for.
If adding a TB doesn't produce a gain, then its not the restriction at whatever power level you are at for the power adder that you are using....+/- 10hp is probably within the margin of error/variance and one would have to question if its even worth talking about. None of what has been posted proves that a 95 or 102 is worth it, cuz it hasn't really been used on a combo that needs it.
If one is talking about a stock-ish engine with a PD supercharger, the stock throttle may not be a restiction and you can get whatever part throttle response you want by asking for it correctly in the calibration tables. If you are blowing through the throttle (centrifugal or turbo), the bar moves even higher with regard to how much a stock TB is good for.
